Acrylonitrile-isobutylene copolymers and process of making same

Claim 1

A PROCESS OF MAKING A READILY FUSIBLE RESINOUS ACRYLONITRILE-ISOBUTYLENE COPOLYMER OF UNIFORM COMPOSITION AND HAVING A FLOW TEMPERATURE OF FROM 100 TO 125* C. WHICH COMPRISES HEATING AN AQUEOUS EMULSION COMPRISING TOTAL AMOUNT OF ISOBUTYLENE TO BE EMPLOYED, AN EMULSIFYING AGENT, AND A POLYMERIZATION CATALYST, AT AN ELEVATED TEMPERATURE OF FROM 30* TO 75* C., AT WHCH TEMPERATURE COPOLYMERIZATION OF ISOBUTYLENE WITH ACRYLONITRILE OCCURS, ADDING ACRYLONITRILE TO THE POLYMERIZATION MIXTURE AT SUCH A RATE THAT THE PROPORTION OF UNREACTED ACRYLONIRTILE RELATIVE TO UNREACTED ISOBUTYLENE IN THE SAID EMULSION INCREASES CONTINUALLY WITH ADVANCING CONVERSION OF THE SAID MONOMERS TO THE COPOLYMERIC STATE, THE SAID RATE OF ADDITION OF ACRYLONITRILE BEING SO SCHEDULED THAT THE END OF THE INDUCTION PERIOD FROM 5 TO 35% TO BE ADDED HAS BEEN ADDED, AND ACRYONITRILE TO BE ADDED HAS BEEN ADDED, AND THEREAFTER WHILE MAINTAINING SAID CONDITIONS ADDING THE BALANCE OF THE ACRYCLONITRILE GRADUALLY AT SUCH A RATE THAT THE TOTAL AMOUNT OF ACRYLONITRILE HAS BEEN ADDED WHEN A CONVERSION OF FROM 50 TO 85% HAS BEEN ATTAINED, AND THE RATE OF ADDITION BEING SUCH THAT NOT MORE THAN 35% OF THE TOTAL QUANTITY OF ACRYLONITRILE IS ADDED OVER THE COURSE OF ANY 20% INCREMENT OF CONVERSION TAKING PLACE DURING THE ADDITION THEREOF, AND NOT LESS THAN 27% OF THE TOTAL QUANTITY OF ACRYLONITRILE IS ADDED OVER THE COURSE OF ANY 30% INCREMENT OF CONVERSION TAKING PLACE DURING THE ADDITION, THE OVERALL CHARGE OF MOMERIC MATERIAL CONSISTING OF ACRYLONITRILE AND ISOBUTYLENE IN PROPORTIONS OF FROM 1.5 TO 3 MOLES OF ACRYLONITRILE PER MOLE OF ISOBUTYLENE, THE HIGHER PROPORTIONS OF CHARGED ACRYLONITRILE WITHIN THE AFORESAID RANGE RESULTING IN CORRESPONDINGLY HIGHER PROPORTIONS OF COMBINED ACRYLONITRILE IN THE PRODUCT, AND RECOVERING FROM THE REACTION MIXTURE THE RESULTING COPOLYMER PRODUCT, SAID COPOLYMER PRODUCT HAVING THE ABOVE CHARACTERISTICS, AND EVERY INCREMENT OF THE SAID COPOLYMER HAVING SUBSTANTIALLY THE SAME CHEMICAL AND PHYSICAL PROPORTIES AS EVERY OTHER INCREMENT THEREOF.